In this study, the relationship between histochemical properties and physico-chemical properties of M. longissimus dorsi was investigated. The carcasses were obtained from forty Hanwoo steers slaughtered at 22 through 26 months old and raised under the same feeding conditions in the feedlot. Marbling score and quality grade of experimental carcasses were evaluated 3.7, 1.43, respectively. Moisture content was 67.44%, crude fat contents was 10.60%, water holding capacity(WHC) was 75.1%, and shear force value(SFV) was 13.55 ㎏. 30.2% of all muscle fibers was identified as type β R while was 25.0% for type α R, and 44.6% for type α W. The diameter of type β R fibers was 50.3 ㎛, that of type a R was 52.8 ㎛ and that of type αW was 64.5 ㎛. Cold carcass weight was significantly (P$lt;0.01) and positively related to area of M. longissimus thoracis. Backfat thickness was negatively correlated with yield Bade (P$lt; 0.001). Marbling degree was significantly and positively related to quality grade (P$lt; 0.001), while negatively related to moisture contents, but positively related to contents of crude fat (P$lt; 0.001). The SFV was positively correlated with quality grade (P$lt; 0.05), indicating that a high SFV means low quality Bade. The percentage of type β R fiber was positively related to marbling number (P$lt;0.01), but it was negatively related to meat color number and quality grade (P$lt;0.05). And the percentage of tyke α R was negatively correlated with backfat thickness, quality grade and SFV. The percentage of type α W was positively correlated with backfat thickness, quality grade and SFV. This data indicates that a relationship exists between the amount of type β R fibers and the marbling score, with increase in type β R fibers being associated with increase in marbling score, higher quality grade, and decrease in SFV.